When sharpening a saw chain, in addition to filing or grinding the depth gauges and rounding the latter, the teeth of the chain are ground. However, according to the type of teeth used on the chain, the teeth must be ground such that the top plate filing angle, top plate cutting angle and side plate filing angle are reasonably precise within predetermined limits. While various guides heretofore have been provided to facilitate hand sharpening of chain saw teeth the majority of recent development in chain saw sharpening has been in the area of supporting a power driven rotary grinding wheel and a saw chain tooth to be sharpened in proper relationship whereby the chain tooth may be properly sharpened by the wheel. It is also important to provide an apparatus whereby successive teeth on each side of a chain may be substantially identically sharpened and that the teeth on opposite sides of the chain be substantially identically sharpened.
To this end many motor driven grinding wheel equipped saw chain sharpeners heretofore have been provided such as those disclosed in U.S. Pat. Nos. 2,811,873, 3,013,448, 3,071,026, 3,717,051, 3,779,103, 4,299,142 and 4,336,726. These motor driven rotary grinding wheel equipped sharpeners provide various structures whereby successive teeth to be sharpened may be disposed in position for relative movement toward and away from the periphery of the associated rotary grinding wheel.
However, many of these previously known sharpeners include extensive structure for mounting a rotary grinding wheel and chain tooth to be sharpened for movement relative to each other and wherein such extensive structure incorporates various types of connections between relatively movable components inherently including clearances which ultimately result in a non-precise guiding movement between the rotary grinding wheel and the saw tooth to be sharpened as the tooth and rotary grinding wheel move into and out of engagement with each other. This non-precise guided movement often results in variations in the sharpening of teeth not only on one side of a chain but also differences in the manner in which teeth on opposite sides of the chain are sharpened.
Therefore, an need exists for a saw chain sharpener incorporating a rotary grinding wheel and including structure whereby precise relative movement between the rotary grinding wheel and a tooth to be sharpened may be obtained.
In addition, a further need exists for a chain sharpener including structure whereby the sharpener may be readily adjusted to sharpen the teeth of either a round chain or a chisel chain.
The main object of this invention is to provide a chain saw sharpener which is capable of providing precise relative movement between a rotary grinding wheel and a chain tooth to be sharpened.
Another object of this invention is to provide a sharpener in accordance with the preceding object and constructed in a manner whereby it may be quickly adapted for sharpening the teeth of either a round chain or a chisel chain.
Still another important object of this invention is to provide a sharpener which may be either bench mounted or stand mounted.
A further object of this invention is to provide a chain saw sharpener which will be capable of allowing lateral movement of the associated grinding wheel thereof away from the tooth surface being ground upon initial radial displacement of the grinding wheel from the tooth being ground.
A final object of this invention to be specifically enumerated herein is to provide a chain saw tooth grinder in accordance with the preceding objects and which will conform to conventional forms of manufacture, be of simple construction and easy to use so as to provide a device that will be economically feasible, long lasting and relatively trouble free in operation.
These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.